Search PubMed⌕ Search

Biomedical subjects

S Saini

Publications and source records attributed to S Saini.

At least 109 records · Page 6Linked to original sources
PubMed1996

Homologues of murine Vh11 gene are conserved during evolution.

Since the murine Vh11 gene family shows 75% homology with group III VH gene families and is preferentially expressed in B-1 lymphocytes, we have analyzed if corresponding Vh11 genes existed across phylogenetically distant mammalian lineages. In a Southern blot, homologues of the murine Vh11 gene were detected in the genomic DNA from rats, pigs, sheep, cattle, horses, dogs and man. These observations suggest conservation of corresponding sequences of the Vh11 gene family during evolution, similar to group III VH genes, either because of strong selection pressures essential for species fitness and survival or molecular drive leading to these consequences.

Animals↗
PubMed1995

Secretory symptoms from metastatic adrenal cortical carcinoma responding to octreotide.

The prognosis of patients with metastatic adrenal cortical carcinoma is poor, and their disabling symptoms are usually unresponsive to conventional therapy. A patient with Cushing's syndrome secondary to a secretory adrenal cortical carcinoma was treated with octreotide, endocrine therapy and chemotherapy having failed. Treatment led to a dramatic relief of her symptoms with a fall in corticosteroid secretion. Somatostatin analogue therapy for this tumour should be encouraged in view of the lack of alternative palliative treatment.

Adrenal Cortex Neoplasms↗
PubMed1995

Adrenal gland enhancement at MR imaging with Mn-DPDP.

PURPOSE: To determine adrenal gland enhancement with manganese (II) N,N' dipyridoxylethylenediamine-N,N'-diacetate 5,5'bis(phosphate) (DPDP) at magnetic resonance imaging. MATERIALS AND METHODS: After phase III trials, fat-suppressed, motion-compensated, T1-weighted spin-echo images (repetition time, 500 msec; echo time, 12 msec) of 13 consecutive patients were obtained at 1.5 T at one site, prior to and approximately 30 minutes after intravenous administration of 5 mumol/kg Mn-DPDP. Images were analyzed visually and by means of region-of-interest measurements, normalized to spleen. With data added from three more sites, enhancement of three adrenal adenomas and two metastases was analyzed. RESULTS: Twenty-five of 26 adrenal glands were depicted on MR images, and all showed enhancement. Mean adrenal enhancement (38%) was comparable to mean enhancement of liver (46%), pancreas (25%), and renal cortex (58%). Adrenal cortex and medulla could not be distinguished in nonenhanced or enhanced images. All three adrenal adenomas enhanced by more than 40%, but the metastases did not enhance. CONCLUSION: Functioning adrenal tissue (glands and at least some adenomas) are enhanced with Mn-DPDP.

Adenoma↗
PubMed1995

Blood-pool MR contrast material for detection and characterization of focal hepatic lesions: initial clinical experience with ultrasmall superparamagnetic iron oxide (AMI-227).

OBJECTIVE: AMI-227 is an ultrasmall superparamagnetic iron oxide colloid known to enhance tissue T1 and T2 relaxation rates. Animal studies show that AMI-227 has an estimated blood half-life of more than 200 min. In this study, we evaluated the clinical utility of AMI-227 as an MR contrast agent for detection and characterization of focal hepatic lesions, with MR imaging done while the contrast agent is in the intravascular space (blood-pool phase). SUBJECTS AND METHODS: Twenty-two patients with known or suspected focal hepatic masses underwent T1- and T2-weighted MR imaging of the liver at 1.5 T before and immediately after drip infusion of AMI-227 at doses of 0.8, 1.1, or 1.7 mg Fe/kg. Unenhanced and contrast-enhanced images were analyzed qualitatively (lesion detection and tissue characterization) and quantitatively (lesion-liver contrast-to-noise ratio). RESULTS: AMI-227 enhanced signal in normal liver and blood vessels on T1-weighted images and decreased signal in these tissues on T2-weighted images. Qualitatively and quantitatively, lesion-liver contrast was increased for solid tumors (non-cyst and nonhemangioma) at all three doses (p < .02) on both T1- and T2-weighted images. Differentiation between blood vessels and small lesions was easier on contrast-enhanced images, which allowed increased confidence in excluding lesions. Unique enhancement patterns were noted for hemangiomas, solid tumors, and cysts. CONCLUSION: Initial clinical experience suggests that AMI-227 is a useful contrast agent for detection and characterization of focal hepatic lesions.

Adult↗
PubMed1995

Characterization of adrenal masses (< 5 cm) by use of chemical shift MR imaging: observer performance versus quantitative measures.

OBJECTIVE: The purposes of this study were to evaluate the ability of chemical shift MR imaging to differentiate 1- to 5-cm adrenal adenomas from metastases and to compare subjective interpretation with several different quantitative measures. SUBJECTS AND METHODS: Forty-three patients with 46 proved adrenal lesions (28 adenomas and 18 metastases) had MR imaging with a gradient-echo breath-hold technique and echo time varied to obtain in-phase and out-of-phase images. Qualitative analysis of the MR images was done by three experienced observers, who reported their confidence in diagnosing the benignity versus the malignancy of the adrenal masses on the basis of signal loss on out-of-phase images. Quantitative analysis was performed by calculating the difference in signal intensity between in-phase and out-of-phase images by use of regions of interest (signal intensity index) and by use of adrenal-liver, adrenal-spleen, and adrenal-muscle signal intensity ratios. Results between quantitative and qualitative measures were compared by use of receiver operating characteristic (ROC) analysis. RESULTS: The mean signal intensity was significantly different between adenomas and metastases on out-of-phase images (64 versus 98) (p < .0005) but not in-phase images (130 versus 122) (p = .47). The adrenal-spleen ratio discriminated between adenomas and metastases better than did the adrenal-liver ratio, the adrenal-muscle ratio, or the signal intensity index. No significant difference in interpretation among the three observers was evident (areas under the ROC curves, 0.93, 0.95, and 0.96). The performance of the observers was comparable to the results obtained with the adrenal-spleen ratio measurement (area under the ROC curve, 0.97). CONCLUSION: Experienced observers were able to differentiate adrenal adenomas from metastases just as well as quantitative measures. The adrenal-spleen ratio is the best quantitative means of distinguishing benign from malignant adrenal masses. Chemical shift MR imaging is a good but imperfect discriminator of adrenal adenomas.

Adenoma↗
PubMed1995

Hepatocellular adenoma: MR imaging features with pathologic correlation.

OBJECTIVE: The purpose of this study was to describe the MR imaging characteristics of hepatic adenomas and to correlate these features with pathologic findings. MATERIALS AND METHODS: Sixteen patients from four institutions who had 31 hepatocellular adenomas underwent MR imaging with T1- and T2-weighted pulse sequences at 1.5 T. Dynamic gadolinium-chelate-enhanced gradient-recalled-echo (GRE) MR imaging was done in eight patients with 15 lesions. Twenty-three lesions in 15 patients were confirmed by surgical excision. MR images were retrospectively reviewed by three experienced radiologists for signal intensity of lesions relative to liver, heterogeneity, contrast enhancement, and presence of signs of histopathologic correlates. These imaging findings were then compared with histopathologic findings. RESULTS: Nearly all (29 of 31 lesions) hepatocellular adenomas showed heterogeneous signal intensity on MR images. Most (19/31) were predominantly hyperintense on proton density- or T2-weighted images; the predominant signal intensity on T1-weighted images varied. Thirteen of 15 lesions showed early arterial enhancement relative to liver on dynamic GRE MR images. MR imaging was most successful in showing intratumoral hemorrhage (10 of 12 histopathologically proven lesions), large intratumoral vessels (five of five), fatty change (three of six), and peliosis (three of three cases). In two lesions, capsules (one of five) and central scars (one of three) were detected. CONCLUSION: Hepatocellular adenomas have a highly variable appearance on MR images because of their varied histologic appearances. Although no definitive MR imaging signal or structural characteristics can be identified, tumor heterogeneity, particularly when related to hemorrhage, and early arterial enhancement can suggest a diagnosis of hepatocellular adenoma in the proper patient population.

Adenoma, Liver Cell↗
PubMed1995

Fast MR imaging: technical strategies.

Since the introduction of MR imaging for medical use in the early 1980s, there has been a continuous trend toward reduction in scan times. Whereas it took over 24 hr to acquire and display the earliest MR images [1], scan times of well under a second are now feasible. The trend toward shorter scan times is based on a need to reduce motion-related artifacts, to provide more comprehensive studies in a reasonable examination time (such as those with multiple pulse sequences, multiple planes, or contrast media), or to increase patient throughput to reduce per-patient examination costs.

Humans↗
PubMed1995

Gadoteridol-enhanced MR imaging of malignant hepatic tumors: effects of triple versus standard doses on lesion-liver contrast.

OBJECTIVE: The purpose of this study was to compare liver signal-to-noise ratio (SNR), lesion SNR, and lesion-liver contrast-to-noise-ratio (CNR) in patients with malignant liver lesions after the administration of a standard dose (0.1 mmol/kg of body weight) or a triple dose (0.3 mmol/kg) of a gadolinium chelate (gadoteridol). We hypothesized that the higher dose would produce a higher lesion-liver CNR and therefore increase the conspicuity of hepatic lesions. MATERIALS AND METHODS: A total of 85 patients with malignant hepatic masses (61 metastases, 22 hepatocellular carcinomas, and two lymphomas) proved by histologic or follow-up studies underwent MR imaging at 1.5 T. T1-weighted spin-echo imaging and gradient-echo imaging were done before and within 1 min after (gradient echo) as well as 5 (spin echo) and 15 (spin echo) min after the injection of 0.1 or 0.3 mmol of gadoteridol per kg, randomized before the start of the study (39 patients received the standard dose, and 46 received the triple dose). The signal intensities of the liver and lesions and the SD of background noise were measured by use of regions of interest to calculate the SNR of the liver and malignant lesions and the lesion-liver CNR. RESULTS: The lesion-liver CNR was increased significantly at 5 and 15 min after the administration of gadoteridol. No significant differences in the liver SNR, lesion SNR, and lesion-liver CNR (after 1 min: standard dose, -5 +/- 8, and triple dose, -4 +/- 14; after 5 min: standard dose, -1 +/- 5, and triple dose, 2 +/- 8; and after 15 min: standard dose, 1 +/- 5, and triple dose, 6 +/- 20) were found between the doses at all time points. CONCLUSION: Triple-dose gadoteridol does not improve the lesion-liver contrast of malignant hepatic lesions over that provided by the standard dose and is not warranted for liver MR imaging.

Adult↗
PubMed1995

Endoscopic retrograde pancreatography: imaging findings.

Endoscopic retrograde pancreatography (ERP) is commonly used in the diagnosis and management of pancreatic disorders. The aim of this pictorial essay is to provide an overview of the common appearances of normal anatomy, anatomic variants, and pancreatic diseases at ERP.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMed1995

Do widowers use the health care system differently? Does intervention make a difference?

OBJECTIVE: To describe the health care use patterns of widowers who had participated in a randomized trial of mutual support, and of a matched cohort of married men DESIGN: Retrospective audit of Ministry of Health use data SETTING: The family practice unit in a general teaching hospital. PARTICIPANTS: The 113 new widowers (61 treatment, 52 waiting-list controls) who participated in a randomized trial of mutual support, and 111 married men matched for age INTERVENTIONS: Mutual support program MAIN OUTCOME MEASURES: Monthly rates of visits to family physicians, psychiatrists, and all other specialists for the three cohorts RESULTS: Visit rates to family physicians and specialists (SPs) for the married men were stable for the 20 months of the study; rates for the widowers rose significantly from the time of loss to the end of the intervention (for FPs, f = 13.18, df = 2, P < .01; for SPs, f = 5.34, df = 2, P = .005). Rates for FPs declined after intervention for the treatment group, but kept rising among the controls (f = 4.17, df = 1, P = .044). CONCLUSIONS: The decreased physician visit rate among those taking part in the mutual support program suggests that this program met some of the widowers' social support needs that would otherwise have led to the use of health care resources.

Aged↗
PubMed1995

[Echo-planar imaging (EPI) of the abdomen].

The time resolution of echoplanar imaging (EPI) allows the acquisition of images < or = 100 ms, thus eliminating motion-related artifacts of the abdomen. Physical limitations are restrictions in signal-to-noise ratio and spatial resolution. Breath-held acquisitions are recommended to avoid spatial misregistrations and to ensure a defined slice position. Clinical studies have demonstrated the usefulness of EPI for the detection and characterization of focal liver lesions. The development of clinical strategies of EPI for abdominal imaging requires the administration of gastrointestinal contrast agents as in computed tomography. Current clinically approved CT contrast agents appear to be applicable for abdominal EPI because of their long relaxation times.

Abdominal Neoplasms↗
PubMed1994

Case report: haemorrhagic hepatic adenoma--MR features.

Hepatic adenomas are incidentally detected with increasing frequency after imaging the abdomen for unrelated pathology. We report the CT and MR features of an asymptomatic hepatic adenoma with evidence of subclinical intratumoral haemorrhage.

Adenoma↗
PubMed1994

Failed metallic biliary stents: causes and management of delayed complications.

OBJECTIVE: To describe the incidence, management and long-term outcome of metal stent failure in patients with malignant biliary obstruction. SUBJECTS AND METHODS: Sixty-nine patients received a total of 93 metallic biliary stents for relief of malignant biliary obstruction. Twenty-nine patients had hilar tumours; 40 had common bile duct tumours. RESULTS: Ten of 69 patients (14%) presented with stent occlusion at a mean interval of 4 months after stent insertion. Five of 29 patients (17%) with hilar lesions and five of 40 patients (12%) with common bile duct lesions had stent occlusion. Occlusion was due to tumour overgrowth in eight patients and to occlusion by debris in two. The eight patients with tumour overgrowth were treated with internal/external catheters (5 patients), no therapy (2 patients), and further metal stents (1 patient). These eight patients with tumour overgrowth had a limited lifespan after tumour overgrowth occurred with a mean survival of 2.6 months. The two patients with occlusion due to debris were treated by sweeping the stent with a balloon catheter and these patients survived 26 and 27 months, respectively. CONCLUSION: Adequate peripheral purchase in the biliary tree and overstenting are necessary to prevent tumour overgrowth when stenting hilar lesions. The development of stent occlusion due to tumour overgrowth heralds a limited survival and internal/external catheters are preferred over further metal stents for palliation.

Adult↗